CN103748801A - Apparatus and method for beamforming in wireless communication system - Google Patents

Abstract

An apparatus and method for generating a frame for communication using beamforming in a wireless communication system are provided. A method for transmitting a signal in a transmission stage includes determining a beam change time of a region for transmitting information in a frame, and transmitting information to a reception stage on the region for transmitting information by considering the beam change time. The frame includes a plurality of regions divided based on the type of information transmitted to the receiving stage, and the plurality of regions include different beam changing times.

Description

Apparatus and method for beamforming in wireless communication system

technical field

The present invention relates to an apparatus and method for beamforming in a wireless communication system. More particularly, the present invention relates to an apparatus and method for generating a frame for communication using beamforming in a wireless communication system.

Background technique

Wireless communication systems may use beamforming techniques to increase data transfer rates. Beamforming is a family of techniques that use high-gain antennas to improve transmission and reception performance.

Using beamforming, wireless communication systems need to reduce the antenna beamwidth in order to increase antenna gain. Wireless communication systems require the use of multiple narrow beams to transmit signals in various directions.

However, since a frame is not defined for communication using beamforming in a wireless communication system, it is necessary to generate a frame for communication using beamforming.

The above information is provided as background information only to assist with an understanding of the present disclosure. No determination has been made, and no representation is made, as to whether any of the above might be applicable as prior art with respect to the present invention.

Contents of the invention

Aspects of the present invention are to address the above-described problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide an apparatus and method for generating a frame for communication using beamforming in a wireless communication system.

Another aspect of the present invention is to provide an apparatus and method for generating a frame for communication using beamforming in a wireless communication system using a plurality of beamforming antennas.

Still another aspect of the present invention is to provide an apparatus and method for generating a frame in which a beam changing time is differently set according to a type of information transmitted using beamforming in a wireless communication system.

Another aspect of the present invention is to provide an apparatus and method for generating a frame adaptively defining a pilot pattern according to the type of information transmitted using beamforming in a wireless communication system.

Still another aspect of the present invention is to provide an apparatus and method for determining the number of symbols constituting a slot by considering a cyclic prefix (CP) length in a wireless communication system.

Still another aspect of the present invention is to provide an apparatus and method for generating a frame such that a symbol at a beam changing point uses a long CP in a wireless communication system.

According to an aspect of the present invention, there is provided a method for transmitting a signal in a transmission stage of a wireless communication system comprising a plurality of antennas and forming a plurality of beams. The method includes: determining a beam change time of an area used for transmitting information of a frame; and transmitting information to a receiving stage by taking into account the beam changing time over the area used for transmitting information, wherein the frame includes information based on information transmitted to the receiving stage A plurality of regions divided by the type, and wherein the plurality of regions include different beam changing times.

According to another aspect of the present invention, an apparatus for transmitting a signal in a transmission stage of a wireless communication system forming a plurality of beams is provided. The apparatus includes: an antenna unit including a plurality of antenna elements; a radio frequency (RF) chain for forming a beam by the antenna unit; The information is transmitted to the receiving stage through a region in which the information is transmitted, wherein the frame contains a plurality of regions divided based on the type of information transmitted to the receiving stage, and wherein the plurality of regions contain different beam changing times.

Other aspects, advantages and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the accompanying drawings, discloses exemplary embodiments of the invention.

Description of drawings

The above and other aspects, features and advantages of certain exemplary embodiments of the present invention will become more apparent from the following detailed description in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates a frame of a wireless communication system according to an exemplary embodiment of the present invention;

2A to 2D illustrate frames of a wireless communication system according to an exemplary embodiment of the present invention;

3A and 3B illustrate reference signals of a wireless communication system according to an exemplary embodiment of the present invention;

FIG. 4 illustrates resource allocation of a wireless communication system according to an exemplary embodiment of the present invention;

5 illustrates a frame of a wireless communication system employing Frequency Division Duplex (FDD) according to an exemplary embodiment of the present invention;

6 illustrates a frame of a wireless communication system employing time division duplex (TDD) according to an exemplary embodiment of the present invention;

Figure 7 illustrates a block diagram of a transceiver according to an exemplary embodiment of the present invention;

8A and 8B illustrate a radio frequency (RF) chain according to an exemplary embodiment of the present invention;

Figure 9 illustrates an RF chain according to an exemplary embodiment of the present invention;

FIG. 10 illustrates a block diagram of a receiving stage according to an exemplary embodiment of the present invention;

11 is a flowchart illustrating a method for transmitting a signal using beamforming in a transmission stage according to an exemplary embodiment of the present invention;

12 is a flowchart illustrating a method for receiving a signal in a receiving stage according to an exemplary embodiment of the present invention;

13 is a flowchart illustrating a method for transmitting a signal using beamforming in a transmission stage according to an exemplary embodiment of the present invention; and

14 is a flowchart illustrating a method for receiving a signal in a receiving stage according to an exemplary embodiment of the present invention.

Throughout the drawings, it should be noted that like reference numerals will be understood to refer to like parts, components and structures.

Detailed ways

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the present invention as defined by the claims and their equivalents. This description includes various specific details to aid in understanding but should be regarded as exemplary only. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions may be omitted for conciseness and clarity.

The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents .

It should be understood that the singular forms "a", "the" and "said" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

By the term "substantially" is meant that the recited characteristic, parameter or value need not be achieved exactly, but there may be deviations or changes in the amount, including for example, tolerances, measurements Errors, limitations of measurement precision, and other factors known to those skilled in the art.

Exemplary embodiments of the present invention provide a technique of generating a frame for communication using beamforming in a wireless communication system.

Hereinafter, it is assumed that a wireless communication system employs an antenna beamforming technique. This antenna beamforming technology forms beams by changing the phase of radio frequency signals transmitted and received through each antenna.

1 through 14, discussed below, and the various embodiments used to describe the principles of the disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged communications system. The terms used to describe various embodiments are exemplary. It should be understood that they are provided only to aid in the understanding of the description, and that their use and definitions in no way limit the scope of the invention. The terms first, second, etc. are used to distinguish objects with the same term and are by no means intended to indicate a chronological order unless explicitly stated otherwise. A collection is defined as a non-empty collection that includes at least one element.

FIG. 1 illustrates a frame of a wireless communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the frame includes a plurality of fixed-length subframes, and one subframe includes a plurality of fixed-length slots. One slot consists of a number of fixed-length symbols. For example, the frame may include 5 subframes, one subframe may include 20 slots, and one slot may include 10 or 11 symbols. In this case, the number of symbols constituting a slot is determined by the length of a cyclic prefix (CP) of each symbol. For example, when a 50us time slot includes 10 symbols, the length of each symbol is 5us and the CP length of each symbol is 1us. For example, when a 50us time slot includes 11 symbols, the length of the first symbol of the time slot is 5us and the length of the remaining 10 symbols is 4.5us. At this time, the CP length of the first symbol of the slot is 1 us and the CP length of the remaining 10 symbols is 0.5 us.

The wireless communication system divides a frame into a first slot for at least one of a synchronization signal and common control information, a training signal slot, a control slot, and a data slot. The time slots can be structured as shown in FIG. 2 according to the characteristics of the information transmitted through the corresponding time slots. Here, the first slot may include any one of a slot for synchronization signals and common control information, a slot for synchronization signals, and a slot for common control information. Hereinafter, it is assumed that the first slot is a slot for synchronization signals and common control information.

2A to 2D illustrate frames of a wireless communication system according to an exemplary embodiment of the present invention.

Figure 2A illustrates time slots for synchronization signals and common control information, Figure 2B illustrates subframes for data and control information, Figure 2C illustrates control time slots, and Figure 2D illustrates random access channel time slots.

Referring to FIG. 2A, a time slot for synchronization signals and common control information is a minimum unit for carrying synchronization signals and common control information in the frame, and is located in a designated area of the frame. The transmitting stage repeatedly transmits the synchronization signal and the common control information while changing the beam of each antenna beam within the time slot for the synchronization signal and the common control information so that the receiving stage can receive the synchronization signal and the common control information anywhere in the cell. Public Control Information. For example, when time slot #2 of subframe #0 in FIG. 1 is a time slot for synchronization signals and common control information, the transmitting stage transmits synchronization signals and common control information through time slot #2 of subframe #0 of each frame. control information. In this case, the transmission stage transmits synchronization signals and common control information using symbols #0 and #1 using transmit beam #0, and transmits synchronization signals and common control information using symbols #2 and #3 using transmit beam #1. information, and use transmit beam #2 to transmit synchronization signals and common control information using symbols #4 and #5. Here, the common control information includes control information transmitted on a frame basis, such as a cell identifier, system and cell common system information for cell access and reception level migration, and frame configuration information. For example, according to the 3rd Partnership Project (3GPP) standard, the common control information includes a part or all of a master information block (MIB), a system information block (SIB1) and a SIB2. That is, the common control information includes the number of antenna layers, downlink bandwidth, base station and cell identifier, public land mobile network (PLMN) identifier, uplink frequency, uplink bandwidth, duplex type, random access Resource allocation information, and the number of frames.

The transmitting stage transmits the synchronization signal and the common control information, either of which includes a beam identifier so that the receiving stage can identify the beam to receive the synchronization signal and the common control information. For example, when the synchronization signal carries the beam identifier, the sending stage does not have to send the synchronization signal and the common control information successively. That is to say, the sending stage can send common control information through other fixed time slots that are not adjacent to the synchronization signal. For example, when the common control information carries the beam identifier, the sending stage needs to send the synchronization signal and the common control information successively.

As described above, although the transmission position of the synchronization signal is fixed in the frame, the number of slots used for the synchronization signal and common control information may vary. For example, the number of slots for synchronization signals and common control information may differ according to the number of transmit beams of the transmit stage.

Referring to FIG. 2B , in one subframe, at least one slot is allocated to a control slot for carrying control information, and other slots are allocated to data slots for carrying data. Here, for each subframe, the numbers of control slots and data slots in a subframe may be different.

All symbols in a data slot use the same beam. When the data slot is changed, the beam used to transmit the data can be changed. For example, the transmitting stage transmits data using beam #3 through slot #1 and using beam #0 through slots #2 and #3. That is, the minimum unit for carrying user data using the same beam is defined as a slot. Therefore, one slot can be set as one transmission time interval (TTI), so that a receiving stage receiving only one slot can decode the data.

When slot #0 is allocated to the control slot in the subframe of FIG. 2B , the control slot (slot #0 ) is structured as shown in FIG. 2C .

Referring to FIG. 2C , a control slot can change a beam for carrying control information based on at least one symbol. For example, the transmitting stage transmits control information using beam #3 through symbol #0, using beam #0 through symbol #1, and using beam #5 through symbol #9. Here, the control information includes resource allocation information for data transmission.

Referring to FIG. 2D, each resource in one slot may be allocated to a random access channel slot. At this time, the resource allocation information of the random access channel time slot is carried to the receiving stage through common control information.

Using random access channel slots, the receiving stage sends a random access preamble and random access information signals. When the receiving stage knows the optimal transmission beam of the transmitting stage, the receiving stage transmits the random access preamble and the random access information signal only once using the optimal transmission beam. In contrast, when the receiving stage does not know the optimal transmission beam of the transmitting stage, the receiving stage repeatedly transmits the random access preamble and the random access information signal while changing the direction of the transmitting beam. Here, the random access preamble indicates a signal for detecting synchronization of an uplink signal. The random access information signal includes receiving stage information including a transmit beam identifier of the receiving stage.

The transmitting stage receives random access signals using one beam within one time slot. When the time slot is changed, the transmitting stage receives the random access signal by changing the beam. Here, the random access signal includes a random access preamble and a random access information signal.

In this exemplary embodiment, the random access channel slot uses the resources of one slot. Alternatively, the random access channel slots may use a portion of the resources of the data slots.

In a frame of this wireless communication system, beam changing times differ according to channel types. The frame can be structured such that symbols with long CPs can be placed at beam changing points. For example, when the control slot of FIG. 2C can change the beam based on at least one symbol, a long CP (1us) is used for each symbol. Therefore, the control slot can include 10 symbols based on the long CP. Similar to the control slot, a slot for a synchronization signal and a control signal, and a training signal slot, which can change beams based on at least one symbol, can apply a long CP for each symbol. For example, the data slots of Figure 2B, which can change beams on a slot basis, use a long CP (1us) in the first symbol. In this case, a short CP (0.5us) can be applied to other symbols of the data slot except the first symbol to increase transmission efficiency, or a long CP (1us) can be applied according to channel characteristics. When symbols other than the first symbol of the data slot use a short CP, the data slot can include 11 symbols. In contrast, when symbols other than the first symbol of the data slot use the long CP, the data slot can include 10 symbols.

As such, each symbol can include CPs of different lengths. However, the frame includes the slots of the same length. Therefore, the frame can be configured such that slots including symbols having different CP lengths can coexist. In this case, the frame can selectively use the optimal length CP based on channel characteristics and beam change time.

As mentioned earlier, data slots and control slots have different units for beam changes. Accordingly, the sending stage may send a reference signal, such as a pilot as shown in FIG. 3 .

3A and 3B illustrate reference signals of a wireless communication system according to an exemplary embodiment of the present invention.

FIG. 3A illustrates a reference signal for a data slot, and FIG. 3B illustrates a reference signal for a control slot. A data slot is assumed to include 11 symbols.

Referring to FIG. 3A , the data slot, which changes a beam on a slot basis, generates a reference signal on a slot basis. For example, the data slot can carry four independent Quadrature Amplitude Modulation (QAM) or Phase Shift Keying (PSK) symbols together in each symbol's subcarrier.

Referring to FIG. 3B , the control slot, which changes a beam based on at least one symbol, generates a reference signal based on at least one symbol.

With the frame constructed as above, resources can be allocated as shown in FIG. 4 .

FIG. 4 illustrates resource allocation of a wireless communication system according to an exemplary embodiment of the present invention.

With reference to Fig. 4, sending level can allocate the resource of data time slot #4, #5 and #6 to the receiving level #3 that uses beam #1, and the resource allocation of data time slot #7 and #8 is allocated to using beam # 1's receiving stage #4.

In addition, the transmission stage can allocate resources of slots #9 to #13 to reception stages #5 and #6 using beam #4. Resources allocated to slots #9 to #13 of reception stages #5 and #6 are divided into different frequency resources.

When a frequency division duplex (FDD) frame is generated using the above frame structure, the wireless communication system can generate the FDD frame as shown in FIG. 5 .

FIG. 5 illustrates a frame of a wireless communication system employing FDD according to an exemplary embodiment of the present invention.

Referring to FIG. 5, according to FDD, downlink and uplink occupy different frequency resources. Therefore, the FDD frame is generated such that the downlink frame and the uplink frame occupy different frequencies.

The downlink frame and the uplink frame each include 5 subframes, and one subframe includes 20 slots. One slot includes 10 or 11 symbols.

The downlink frame assigns slot #0 of each subframe to a control slot and assigns slot #2 of subframe #0 to a synchronization signal and common control information slot.

The downlink frame allocates slot #5 of each subframe to training signal slots and the other slots to data slots.

The uplink frame allocates slot #0 of each subframe to a control slot and allocates the other slots to data slots. Here, the control information transmitted by the receiving stage through the uplink control slot includes hybrid automatic repeat request (HARQ), acknowledgment/non-acknowledgement (ACK/NACK) information, channel quality indicator (CQI) feedback information, precoding matrix indication PMI information, rank indicator information, scheduling request information, transmission beam information of the base station, and training signal request information.

The wireless communication system is capable of generating time division duplex (TDD) frames as shown in FIG. 6 .

FIG. 6 illustrates frames of a wireless communication system employing TDD according to an exemplary embodiment of the present invention.

Referring to FIG. 6, according to TDD, downlink and uplink occupy different time resources. Therefore, the TDD frame divides downlink frames and uplink frames using time resources.

The TDD frame includes 5 subframes, and one subframe includes 20 slots. One slot includes 10 or 11 symbols.

In one subframe, slots #0 to #10 are allocated to downlink frames, and slots #11 to #19 are allocated to uplink frames.

The downlink frame assigns slot #0 of each subframe to a downlink control slot and assigns slot #2 of subframe #0 to a synchronization signal and common control information slot.

The downlink frame allocates slot #5 of each subframe to training signal slots and the other slots to data slots.

The uplink frame allocates slot #11 of each subframe to uplink control slots and the other slots to data slots.

Slot #10 of each subframe is used as a CP for operation switching. A CP (not shown in the figure) for operation switching is inserted between subframes.

As such, training signal time slots are assigned to narrow beams that are selected for transmitting and receiving data. During the training signal slot, the transmitting stage can change the beam direction based on at least one symbol. Here, the training signal slots are allocated to fixed positions periodically, as shown in FIGS. 5 and 6, or may be allocated aperiodically according to the request of the receiving stage.

The synchronization signal carries the beam identifier using part of the synchronization signal code or using common control information. The training signal does not directly carry the beam identifier, but can indirectly inform the beam identifier using the position and order of the training signals in the training signal slot.

The training signals in the training signal slots should be chosen to minimize inter-cell interference. For example, the training signal is arranged at regular subcarrier intervals like the reference signal of FIG. 3B , and the location of the training signal is different in each cell. For example, training signal sequences may be generated orthogonally from cell identifiers to mitigate interference.

The wireless communication system is capable of providing communication services using a plurality of different bandwidths. Therefore, frames of wireless communication systems need to be designed to support multiple bandwidths.

To support these bandwidths, the frame is designed such that synchronization signals and common control information are sent using the minimum bandwidth while other signals occupy the entire frequency band. For example, when supporting a bandwidth of 1GHz with 16 resource blocks (RBs), the wireless communication system can support four bandwidths: 125MHz, 250MHz, 500MHz, and 1GHz. Therefore, this frame allocates synchronization signals and common control information to two center RBs corresponding to the minimum bandwidth of 125 MHz, and allocates other signals to the entire frequency band of 1 GHz.

As such, a control slot for control information is provided separately. When the amount of control information sent by the transmitting stage matches the multiple of the resource amount of the time slot, unnecessary resource waste of the control time slot will not occur. However, when the amount of control information sent by the sending stage does not match the multiple of the resource amount of the time slot, the control slot generates unnecessary waste of resources. For example, when one slot includes 10 symbols and the transmitting stage needs 12 symbols to transmit control information, the frame allocates two slots to the control slot. In this case, eight symbols of the second control slot would be wasted unnecessarily.

In order to reduce the resource waste of the control slot, when the amount of control information sent by the sending stage does not match the multiple of the resource amount of the time slot, the sending stage can send the control information by puncturing a part of the data slot. When the reference signal of the data slot is punctured to transmit the control information, the channel estimation performance at the receiving stage may be degraded. Therefore, the transmitting stage can mitigate the performance degradation caused by puncturing by evenly distributing the reference signals over the slots as shown in FIG. 3A .

In this exemplary embodiment, the transmit stage punctures data slots for control information. Similarly, the transmit stage can transmit synchronization signals and common control information or training signals by puncturing data slots.

FIG. 7 illustrates a block diagram of a transceiver according to an exemplary embodiment of the present invention.

Referring to FIG. 7 , the transceiver includes a controller 700 , a beam selector 710 , an antenna unit 720 , a transmitter 730 and a receiver 740 .

The controller 700 controls the operation of the transceiver.

According to any one of the frame structures of FIGS. 1, 5, and 6, the controller 700 forms beams to transmit synchronization signals and common control information, control information, training signals, and data. For example, the controller 700 transmits the synchronization signal and common control information through a synchronization signal and common control information slot placed in a designated area of a frame. In this case, the controller 700 repeatedly transmits the synchronization signal and the common control information while changing the beam per antenna beam within the synchronization signal and common control information slot as shown in FIG. 2A . The controller 700 transmits the synchronization signal and the common control information, either of which includes a beam identifier so that the receiving stage can identify the beam to receive the synchronization signal and the common control information.

For example, the controller 700 changes beams based on slots in a region allocated to data slots in a subframe, as shown in FIG. 2B . In this case, the controller 700 transmits a reference signal based on a time slot of data slots, as shown in FIG. 3A .

For example, the controller 700 changes beams based on at least one symbol in a region of a subframe allocated to a control slot, as shown in FIG. 2C . In this case, the controller 700 transmits a reference signal based on at least one symbol in the control slot, as shown in FIG. 3B .

For example, when a random access signal is received through random access channel slots allocated as shown in FIG. 2D , the controller 700 receives the random access signal using one beam within one slot. When a random access signal is transmitted through a random access channel slot, the controller 700 transmits the random access signal once using an optimal transmission beam for carrying the random access signal. When the optimum transmission beam is not known, the controller 700 repeatedly transmits the random access signal by changing the direction of the transmission beam.

For example, the controller 700 sends training signals through fixed-position training signal time slots. The training signal time slots may be allocated aperiodically. The controller 700 may change the beam based on at least one symbol within the training signal slot.

For example, the controller 700 may transmit at least one of control information, a synchronization signal and common control information, and a training signal by puncturing a part of a data slot. In this case, the controller 700 may send the puncturing information of the data slot to the receiving stage using the control information.

The beam selector 710 selects beams with corresponding patterns under the control of the controller 700 . During the transmit beamforming process, the beam selector 710 transmits the selected beam pattern information to the transmitter 730 . During the receive beamforming process, the beam selector 710 sends the selected beam pattern information to the receiver 740 .

The antenna unit 720 includes a plurality of antenna elements. For example, the antenna unit 720 includes a plurality of omnidirectional antenna elements, as shown in FIGS. 8A and 8B . For example, the antenna unit 720 may comprise a plurality of directional antenna elements for transmitting signals in different directions, as shown in FIG. 9 .

The transmitter 730 includes a transmit modem 732 and a transmit RF chain 734 .

The transmit modem 732 encodes and modulates data for transmission through an antenna to a receiving stage, and converts the modulated signal into an analog signal. The transmit modem 732 sends the analog baseband signal to the transmit RF chain 734 .

The transmit RF chain 734 includes a plurality of RF paths for delivering signals to the antenna elements. In this case, the transmit RF chain 734 may use only some antenna elements and some RF paths with the beam pattern and beam width selected by the beam selector 710 .

8A and 8B illustrate a radio frequency (RF) chain according to an exemplary embodiment of the present invention, and FIG. 9 illustrates an RF chain according to an exemplary embodiment of the present invention.

7, FIG. 8A, FIG. 8B and FIG. 9, the transmit RF chain 734 multiplexes the baseband signal output from the transmit modem 732 into at least one active RF path, converting the corresponding baseband signal in each RF path into an RF signal and transmit the signal through the antenna unit 720. In this case, the transmit RF chain 734 steers the baseband signals to form beams in the beam pattern selected by the beam selector 710 . For example, when the antenna unit 720 includes omnidirectional antenna elements as shown in FIG. 8A, the transmit RF chain 734 includes phase shifters 800-1 to 800-N for changing the phase shifters at the antenna elements 810-1 to 810-N. The phase of the signal transmitted in each RF path. The phase shifters 800-1 to 800-N change the phase of a signal to be transmitted through each antenna element according to the beam pattern and beam width selected by the beam selector 710.

For example, when the antenna unit 720 includes a plurality of directional antenna elements 910-1 through 910-N as shown in FIG. even. The switch 900 interconnects at least one antenna element and the transmit modem 732 according to the beam pattern and beam width selected by the beam selector 710 . Here, the switch 900 can interconnect a transmit modem 732 and at least one antenna element.

The receiver 740 includes a receive RF chain 742 and a receive modem 744 .

The receive RF chain 742 includes a plurality of RF paths for RF signals received via the antenna elements. In this case, the receive RF chain 742 may use only some antenna elements and some RF paths according to the beam pattern and beam width selected by the beam selector 710 .

The receive RF chain 742 converts the RF signals received from the antenna elements to baseband signals and sends the baseband signals to the receive modem 744 . In this case, the receive RF chain 742 steers the baseband signals to form beams in the beam pattern selected by the beam selector 710 . For example, when the antenna unit 720 includes multiple omnidirectional antenna elements as shown in FIG. 8A, the receive RF chain 742 includes phase shifters 820-1 to 820-N for changing N is the phase of the received signal. The phase shifters 820-1 to 820-N change the phase of a signal received through each antenna element according to the beam pattern and beam width selected by the beam selector 710.

For example, when the antenna unit 720 includes directional antenna elements 910-1 through 910-N as shown in FIG. 9, the receive RF chain 742 includes a switch 900 for interconnecting the receive modem 744 and the antenna elements according to the beam pattern. The switch 900 interconnects at least one antenna element and the receive modem 744 according to the beam pattern and beam width selected by the beam selector 710 . Here, the switch 900 may interconnect a receive modem 744 and at least one antenna element.

The receive modem 744 converts the analog signal output from the receive RF chain 742 into a digital signal, and demodulates and decodes the digital signal.

In this exemplary embodiment, the transceivers share a single antenna element 720 . Alternatively, different antenna elements can be used for the transmitter and receiver. Alternatively, the transmitter and receiver can be separate modules.

As described above, the antenna unit 720 of FIG. 8A or 8B changes the phase of each antenna element or changes the switch according to the structure of FIG. 9 . During changing phases or switches, the antenna element 720 experiences a delay for stabilization due to physical limitations of the elements. Therefore, in order to mitigate the interference from the beam change of the antenna unit 720, the transmit stage may use symbols with long CP at the beam change point.

FIG. 10 illustrates a block diagram of a receiving stage according to an exemplary embodiment of the present invention.

Referring to FIG. 10 , the receiving stage includes a duplexer 1001 , a receiver 1003 , a controller 1005 , a beam selector 1007 and a transmitter 1009 .

The duplexer 1001 transmits the transmission signal output from the transmitter 1009 through the antenna according to the duplex method and supplies the signal received from the antenna to the receiver 1003 .

The receiver 1003 converts the RF signal fed from the duplexer 1001 into a baseband signal and demodulates the baseband signal. For example, the receiver 1003 may include RF processing blocks, demodulation blocks, channel decoding blocks, and message processing blocks. The RF processing block converts the RF signal fed from the duplexer 1001 into a baseband signal. The demodulation block extracts data from each subcarrier by applying a Fast Fourier Transform (FFT) to the signal output from the RF processing block. The channel decoding block includes a demodulator, a deinterleaver and a channel decoder. The message processing block extracts control information from the received signal and provides the extracted control information to the controller 1005 .

The controller 1005 controls the operation of the receive stage. For example, the controller 1005 acquires synchronization with the base station by detecting a transmission beam of the transmission stage of maximum received power using a synchronization signal periodically received from the transmission stage through a synchronization signal and a common control information slot. The controller 1005 initially accesses the transmit stage by receiving common control information from the transmit stage through the detected transmit beam of the transmit stage.

For example, the controller 1005 controls the beam selector 1007 to select a beam for receiving data.

For example, the controller 1005 receives control information and data through the beam selected by the beam selector 1007 . The controller 1005 can use control information and reference signals for data to estimate channels. For example, the controller 1005 estimates the channel using a slot-based reference signal of the data as shown in FIG. 3A. For example, the controller 1005 may use a symbol-based reference signal of control information as shown in FIG. 3B to estimate the channel. That is, the controller 1005 estimates a channel using the reference signal received by the beam selected by the beam selector 1007 among the reference signals transmitted by the transmission stage by changing the beam every symbol in the control slot.

The controller 1005 sends control information to the sending stage through a control slot of an uplink frame and sends data to the sending stage through a data slot. The control slots of the uplink frame are generated as shown in Figure 2C and the data slots are generated as shown in Figure 2B.

The beam selector 1007 selects an optimum beam for receiving control information and data using a training signal supplied from a transmission stage through a training signal time slot. For example, the beam selector 1007 selects a transmission beam of a transmission stage for transmitting control information and data using a training signal, and selects a reception beam for receiving control information and data from the transmission stage.

The transmitter 1009 encodes and converts data and control messages to be transmitted to the transmission stage into RF signals, and outputs the RF signals to the duplexer 1001 . For example, the transmitter 1009 may include a message generation block, a channel coding block, a modulation block, and an RF processing block.

The message generation block generates a control message including information of the narrow beam selected by the beam selector 1007 . For example, the message generation block generates a control message including beam information selected by the beam selector 1007 . In another example, the message generating block generates at least one control message among control information, sounding signal and training signal request information to be transmitted through the uplink control slot.

The channel coding block includes a modulator, an interleaver and a channel coder. This modulation block maps the signal output from the channel coding block to a carrier using an inverse FFT (IFFT). The RF processing block converts the baseband signal output from the modulation block into an RF signal and outputs the RF signal to the duplexer 1001 .

FIG. 11 is a flowchart illustrating a method for transmitting a signal using beamforming in a transmission stage according to an exemplary embodiment of the present invention.

Referring to FIG. 11, in step 1101, the sending stage sends the synchronization signal and the common control signal to the receiving stage through the synchronization signal and common control information time slot. For example, the sending stage sends the synchronization signal and the common control information through the fixed time slots of the synchronization signal and the common control information in the frame. In this case, the transmission stage repeatedly transmits the synchronization signal and the common control information per antenna beam within the synchronization signal and common control information time slot as shown in FIG. 2A, so that the synchronization signal and the common control information can be Any location within the cell is received. Here, the synchronization signal or the common control information includes the beam identifier.

In step 1103, the sending stage sends a training signal through a training signal time slot. For example, the transmitting stage transmits training signals by changing beam direction to various directions for transmitting data.

In step 1105, the transmitting stage determines whether beam selection information is received from the receiving stage. Here, the beam selection information includes information of the narrow beam selected by the receiving stage. For example, the transmitting stage determines whether beam selection information is received through an uplink control slot.

Upon receiving the beam selection information, in step 1107, the transmitting stage identifies the narrow beam selected by the corresponding receiving stage in the beam selection information.

In step 1109, the sending stage uses the narrow beam selected by the receiving stage to send the control information and data of the receiving stage. For example, the transmitting stage transmits the control information and data of the receiving stage through the control slots and data slots of FIGS. 2B and 2C. In this case, the transmission stage adds reference signals to data on a slot basis, as shown in FIG. 3A , and adds reference signals to control information on at least one symbol basis, as shown in FIG. 3B . Here, the control information includes HARQ ACK/NACK information, power control information, paging information, resource allocation information, signal transmission scheme, transmission beam information, and training signal time slot information. Next, the sending stage ends the process.

In this exemplary embodiment, upon determining that beam selection information has not been received, the transmitting stage waits to receive the beam selection information. Alternatively, when it is determined that no beam selection information is received within the reference time, the sending stage may send the training signal again.

Now, an exemplary method in which the receiving stage receives a signal beamformed by the transmitting stage is explained.

FIG. 12 is a flowchart illustrating a method for receiving a signal in a receiving stage according to an exemplary embodiment of the present invention.

Referring to FIG. 12, at step 1201, the receiving stage acquires synchronization with the sending stage. For example, the receiving stage acquires synchronization with the transmitting stage by detecting the transmit beam of the transmitting stage having the maximum received power using the synchronization signal periodically received from the transmitting stage through the synchronization signal and a common control information time slot .

In step 1203, the receiving stage acknowledges the common control information received from the sending stage. For example, the receiving stage receives common control information from the transmitting stage at the synchronization signal and common control information time slot through the transmitting beam of the transmitting stage detected in step 1201 .

In step 1205, the receiving stage determines whether a training signal is received. For example, the receive stage determines whether a training signal is received through a training signal slot.

Upon receiving the training signal, at step 1207, the receiving stage selects a narrow beam to be used to receive data and sends the data to the transmitting stage. In this case, the reception stage selects a transmission beam of the transmission stage for transmitting control information and data using the training signal, and selects a reception beam for receiving control information and data from the transmission stage.

In step 1209, the receiving stage receives control information and data through the narrow beam. In this case, the receiving stage receives control information and data through the control slots and data slots of FIGS. 2B and 2C. For example, the receiving stage confirms data slots and resource allocation information in control information received through control slots. Next, the receiving stage uses the data slot and the resource allocation information to receive data. At this time, the receiving stage can estimate a channel using reference signals of control information and data. For example, the receiving stage estimates the channel using a slot-based reference signal of the data as shown in FIG. 3A. For example, the receiving stage may use a symbol-based reference signal for control information as shown in FIG. 3B to estimate the channel. That is, the receiving stage estimates a channel using the reference signal received through the beam selected in step 1207 among the reference signals transmitted by the transmitting stage by changing the beam every symbol in the control slot. Next, the receiving stage ends the process.

In this exemplary embodiment, the receiving stage receives signals from the transmitting stage. When the receiving stage has control information and data to be sent to the sending stage, the receiving stage sends the control information to the sending stage through the control slot of the uplink frame of FIG. 5 or FIG. 6, and sends the control information to the sending stage through the data slot Send data to the send stage.

In this exemplary embodiment, the receiving stage transmits the selected narrow beam information to the transmitting stage using the training signal.

Alternatively, the transmitting stage may transmit the training signal using a vertical beam and a horizontal beam, as shown in FIG. 13 . In this case, the receiving stage can send its selected vertical beam and horizontal beam information to the transmitting stage so that the transmitting stage can select a narrow beam. Here, the vertical beam indicates a narrow and vertical long beam, and the horizontal beam indicates a short and wide beam.

FIG. 13 is a flowchart illustrating a method for transmitting a signal using beamforming in a transmission stage according to an exemplary embodiment of the present invention.

Referring to FIG. 13, in step 1301, the sending stage sends the synchronization signal and the common control signal to the receiving stage through the synchronization signal and common control information time slot. For example, the sending stage sends the synchronization signal and the common control information through the fixed time slots of the synchronization signal and the common control information in the frame. In this case, the transmission stage repeatedly transmits the synchronization signal and common control information per antenna beam within the synchronization signal and common control information time slot, as shown in FIG. 2A, so that the synchronization signal and common control information can Received anywhere within the cell. Here, the synchronization signal or the common control information includes the beam identifier.

In step 1303, the sending stage sends a training signal through a training signal time slot. For example, the transmitting stage transmits training signals by changing beam direction to various directions for transmitting data. The sending stage sends the training signal by changing the direction of the vertical beam and the horizontal beam.

In step 1305, the transmitting stage determines whether training signal reception information is received from the receiving stage. Here, the training signal reception information includes information of an optimal vertical beam and an optimal horizontal beam selected by a corresponding receiving stage. The optimum vertical beam indicates a vertical beam having maximum reception power among vertical beams received by the receiving stage, and the optimum horizontal beam indicates a horizontal beam having maximum reception power among horizontal beams received by the reception stage.

When receiving the training signal receiving information, in step 1307, the sending stage uses the optimal vertical beam and horizontal beam selected by the receiving stage and contained in the training signal receiving information to select Send to a narrow beam at the receiving stage. For example, the transmitting stage selects a narrow beam overlapping between an optimal vertical beam and an optimal horizontal beam selected by the receiving stage as the narrow beam to be used for transmitting control information and data to the receiving stage.

In step 1309, the transmitting stage transmits the control information and the data of the receiving stage using the selected narrow beam. For example, the transmitting stage transmits the control information and the data of the receiving stage through the control slot and the data slot of FIG. 2B and FIG. 2C. In this case, the transmission stage adds reference signals to data on a slot basis, as shown in FIG. 3A , and adds reference signals to control information on at least one symbol basis, as shown in FIG. 3B . Next, the sending stage ends the process.

In this exemplary embodiment, when it is determined that the training signal reception information has not been received, the transmission stage waits to receive the training signal reception information. Alternatively, when it is determined that the training signal reception information is not received within the reference time, the sending stage may send the training signal again.

FIG. 14 is a flowchart illustrating a method for receiving a signal in a receiving stage according to an exemplary embodiment of the present invention.

Referring to FIG. 14, at step 1401, the receiving stage acquires synchronization with the sending stage. For example, the reception stage acquires synchronization with the base station by detecting a transmission beam of the transmission stage having maximum reception power using a synchronization signal periodically received from the transmission stage through the synchronization signal and a common control information slot.

In step 1403, the receiving stage acknowledges the common control information received from the sending stage. For example, the receiving stage receives common control information from the transmitting stage on the synchronization signal and common control information time slot through the transmitting beam of the transmitting stage detected in step 1401 .

In step 1405, the receiving stage determines whether a training signal is received. For example, the receive stage determines whether a training signal is received through a training signal slot.

When receiving the training signal, in step 1407, the receiving stage sends the training signal reception information to the sending stage. For example, the transmitting stage transmits training signals using vertical beams and horizontal beams sequentially by changing beam directions. In this case, the receiving stage sends the signal to the transmitting stage by selecting the best vertical beam from the vertical beams and the best horizontal beam from the horizontal beams. Here, the optimum vertical beam indicates a vertical beam having the maximum received power among the vertical beams, and the optimum horizontal beam indicates a horizontal beam having the maximum received power among the horizontal beams.

In step 1409, the receiving stage uses the best vertical beam and the best horizontal beam to select a narrow beam to be used for receiving control information and data. For example, the receiving stage selects a narrow beam overlapping between the optimal vertical beam and the optimal horizontal beam as the narrow beam to be used for receiving data. In this case, the reception stage selects a transmission beam of the transmission stage for transmitting control information and data using the training signal, and selects a reception beam for receiving control information and data from the transmission stage.

In step 1411, the receiving stage receives control information and data through the narrow beam. In this case, the receiving stage receives control information and data through the control slots and data slots of FIGS. 2B and 2C. For example, the receiving stage confirms data slots and resource allocation information in control information received through control slots. Next, the receiving stage uses the data slot and the resource allocation information to receive data. At this time, the receiving stage can estimate a channel using reference signals of control information and data. For example, the receiving stage estimates the channel using a slot-based reference signal of the data as shown in FIG. 3A. For example, the receiving stage may use a symbol-based reference signal for control information as shown in FIG. 3B to estimate the channel. That is, the receiving stage estimates a channel using the reference signal received through the beam selected in step 1409 among the reference signals transmitted by the transmitting stage by changing the beam every symbol in the control slot. Next, the receiving stage ends the process.

In this exemplary embodiment, the receiving stage receives signals from the transmitting stage. When the receiving stage has control information and data to send to the sending stage, it sends the control information to the sending stage through the control slot of the uplink frame of Figure 5 or 6, and sends the data to the sending stage through the data slot The send level.

As described above, depending on the frame used for communication using beamforming in a wireless communication system, the communication can be implemented using beamforming.

In an exemplary embodiment of the present invention, a frame is constructed in a wireless communication system to distinguish a slot for at least one of a synchronization signal and common control information, a training signal slot, a control slot, and a data slot. Therefore, reception performance of the mobile station can be improved, and reception complexity and overhead can be reduced.

The wireless communication system transmits control information by puncturing a portion of the data slot. Therefore, the transmission efficiency of the control information can be increased, thereby reducing waste of resources when transmitting the control information.

Since the control slot is placed at the front of the subframe in this wireless communication system, it is possible to reduce the power consumption of the mobile station by preventing unnecessary data reception.

While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the appended claims and their equivalents. The spirit and scope of the present invention defined by the effects.

Claims (14)

1. for comprising a plurality of antennas and forming the method for transmission level transmitted signal of the wireless communication system of a plurality of wave beams, the method comprises:

Determine in frame and change the time for sending the wave beam in the region of information; And

By considering that this wave beam changes the time, for sending on the region of information, information sent to receiver stage,

Wherein said frame comprises a plurality of regions that the type based on sending to the information of receiver stage is divided, and

The different wave beam of wherein said a plurality of district inclusion changes the time.

2. the method for claim 1, wherein said frame comprises a plurality of subframes, wherein subframe comprises a plurality of time slots, wherein time slot comprises a plurality of code elements, and wherein subframe comprises first area, second area, the 3rd region, at least one in the 4th region and the 5th region, described first area comprises for sending at least one at least one time slot of synchronizing signal and common control information, described second area comprises at least one time slot for sending control information, described the 3rd district inclusion is for sending at least one time slot of data, described the 4th district inclusion is for sending at least one time slot of training signal, and described the 5th district inclusion is for sending at least one time slot of random access signal.

3. method as claimed in claim 2, wherein the transmission of information comprises:

When sending the region of information and be first area, based at least one code element, change wave beam and at least one in synchronizing signal and common control information sent to receiver stage.

4. method as claimed in claim 2, wherein the transmission of information comprises:

When sending the region of information and be second area, based at least one code element, change wave beam and control information is sent to receiver stage.

5. method as claimed in claim 2, wherein second area comprises the reference signal based at least one code element.

6. method as claimed in claim 2, wherein the transmission of information comprises:

When sending the region of information and be the 3rd region, based on time slot, change wave beam and data are sent to receiver stage.

7. method as claimed in claim 2, the wherein timeslot-based reference signal of the 3rd district inclusion.

8. method as claimed in claim 2, wherein the transmission of information comprises:

When sending the region of information and be the 4th region, based at least one code element, change wave beam and training signal is sent to receiver stage.

9. method as claimed in claim 2, also comprises:

In the 5th region, based at least one code element, change wave beam and receive random access signal from described receiver stage.

10. method as claimed in claim 2, wherein the number of a plurality of code elements in time slot is determined by Cyclic Prefix (CP) length of at least one code element.

11. methods as claimed in claim 10, wherein the time slot of second area comprises 10 code elements, and described 10 code elements comprise the CP with the first length, and

The CP with the first length comprises than the long CP of the CP with the second length that can be added at least one code element.

12. methods as claimed in claim 10, wherein the time slot in the 3rd region comprises, 1 code element that comprises the CP with the first length and 10 code elements that comprise the CP with the second length, and

The CP with the first length comprises than the long CP of CP with the second length.

13. methods as claimed in claim 10, wherein the time slot in the 3rd region comprises 10 code elements, and described 10 code elements comprise the CP with the first length, and

The CP with the first length comprises than the long CP of the CP with the second length that can be added at least one code element.

14. 1 kinds for the devices of transmission level transmitted signal forming the wireless communication system of a plurality of wave beams, are configured to realize the method described in claim 1-13.

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